Latest Lifestyle

Home > Health > Health Advice > 9 Things You Never Knew Your Body Does While You Sleep1

9 things you never knew your body does while you sleep

Written By The Good Housekeeping Web team | 22 July 2015

It wakes up a lot more than you realise.

You know you're supposed to get eight hours of sleep a night, but what's really going on up in your body during that time? Quite a lot, it turns out. Here's a peek inside your nighttime body factory.

1. As you fall asleep, you jerk. Every time. According to sleep experts, the degree of the jerk is suggestive of how sleepy you are, so the bigger the jerk, the more tired your body.

2. Your body temperature goes way down. When we're active during the day, we burn more calories, so lowering temperature is a way to reduce the burn rate and save calories. 'It's like how bears hibernate,' says Dr Avi Ishaaya, a sleep specialist and assistant clinical professor of medicine at UCLA. 'Sleep is a survival mechanism.'

3. You do a full toxin cleanse. This allows the body and brain to rejuvenate. In people who don't sleep well, the filtration isn't as effective, so experts say that may help explain why people who are sleep-deprived can go a little crazy.

4. You forget useless information. 'We take in all this information all day long, and most of it is luckily forgotten,' says sleep specialist Christopher Colwell at UCLA School of Medicine. 'If you remembered everything, it would fill up your brain, so a sorting process takes place during sleep.'

5. Your body becomes paralysed, but your brain is its most active. The brain of someone who is dreaming is actually more active than that of a person who is awake, and requires more oxygen. 'One theory is that in REM (rapid eye movement) sleep, you're organising thoughts and learning, filing information, but no one really understands specifically why a sleeping mind is active,' says Dr Alon Y Avidan, a professor of neurology and director of UCLA's Sleep Disorders Centre. Your mind is so active during sleep that it can even make important connections and discoveries, researchers say.

6. All your individual cells — not just your brain cells — are being completely repaired. These restorative processes take care of all the damage that's occurred during the day. When you don't get enough sleep, the effect doesn't just zap your brain — it impacts your whole body. Hence why you feel like you've been beaten up after missing a lot of sleep.

7. Your immune system is at an all-time high. One study showed that people who received flu jabs and were sleep-deprived the next night did not create the antibodies required to protect against the flu. 'As soon as I see the first signs of an upper respiratory infection, I try to sleep for 10 hours,' says Dr. Jordan Stern, founder and director of the BlueSleep Centre in New York City. 'If you're chronically sleep deprived, you're more likely to develop recurring infections.'

8. You wake up between five and 15 times per hour. It usually happens when we shift to different stages of sleep, like from dreams to deep sleep, and the awakenings happen so briefly that we don't remember them.

9. You're probably breathing — a fact most of us take for granted during sleep — but up to 30% of people actually stop breathing at night. Up to 90% of people with this disorder, sleep apnea, go undiagnosed, including young women. Untreated sleep apnoea has been linked with high blood pressure, heart attack and stroke. 'So if you or your partner snores at night, it’s time to get it checked out,' says Dr Stern.

This article was written by Kira Peikoff, and originally appeared on Cosmopolitan.com